A cobpobation of



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more 1 CLEIBURNE A. BASORE, OF PITTSBURGH, PENNSYLVANIA. ASSIGNOR 0F ONE-HALF TO THE KOPPERS COMPANY, OF PITTSBURGH.PENNSYLVANIA. A CORPORATION 011 FEINNSYLVANIA.

No Drawing.

To all whom it may concern:

lie it known that l, (.LnnUuNn llasoun, a citizen at the United States. residing at l-ittsl ,rgh, in the county of Allegheny and State of Pennsylvania, have invented a new and uset'ul Improvement in Purification of Liquids, of which the following is a full, clear, and exact description,

The present invention relates to the purification of liquids and particularly to the purification of the waste liquors tromindustrial plants so that they may discharged into streams without polluting the stream water. The invention is described with particular reference to its embodiment in a process of purifying the waste liquor from the ammonia stills of the by-product coke industry.

it is to be understood. however, that the invention is not limited in its appli .-ation to this industry but may beotherwise employed.

llelerring to the process asemployed or "treating the waste ammonia still liquor:

The raw ammonia still waste has objcw tionable properties which shouldbe removed before it is discharged into a. stream, in order to prevent the pollution of the water there-by. The objectionable properties of the ammonia still waste are its harmful cll'ect on tish. its disagreeable odor, its disagreeable taste and its dark color. These properties are largely due to the presence of phenoloid bodies, thiocvanates and sulfids. Small traces of pyridin and other organic compounds not yet identified maymontribute to its harmful or disagreeable quzdities.

Besides the above impurities there are large quantities of calcium salts, principally calcium chlorid, present, in the waste liquor. However. since the waste liquor is greatly diluted in. the stream to which it is finally drained. the presence of these salts is not particularly objectionable; The present process has to do particularly with the removal of those substances of the ammonia -still. waste which give it its harmful effect Specification of Letters Patent.

Application filed February 15, 1919.

I PURIFICATION OF LIQUIDS.

Pz'ttented Dec. 2, 1919.

Serial No. 277.290.

contact with the air. This causes some evaporation of the water and thereby c0n- I It also permits the (\tiIKlllllllOll of some of the volacentrates the liquor to some extent.

sequent step of treatment in the settling tank. W'hilc'it is preferred to aerate the liquor. this step may be omitted.

ares arana orator...

The liquor is next run into a settling tank I where it. remains for about twenty-four hours. During this time about 95 per cent. of the Pl'GLlplttllOltsolids settle out of the liquid."

The. liquid is drawn next from the settling tank and filtered through an inorganic mai terial. preferably granulated blast furnace slag. This filtration completes the removal of the solids which do not settle out in the settling tank and also removes the tarry matter from the liquor, and if the slag employed contains iron oxids such as are found in the spent slag which results from the treatment of mine water by the process of the. l-leclcman Patent 1,171.0-l6 of February 8th. 1916, the sullids are also removed from the liquor. These sullids exist in the liquor principally as calcium sulfids. The spent blast turnacefslag also partially removes some of the cyanogen compounds. \Vhilc it is preferred to usethc slag with the iron oxide resulting from the treatment of mine atcr or the like. the iron oXids might be otherwise supplied to the slag or inorganic littering material used for this stcp of the access.

The filtered liquor may then be treated tor the removal and recovery of cyanogen compounds. This -is preferably accomplishcd by the addition to the liquor of a compound such as -ferrous salt, which will precipitate the terro-cyanids followed by the addition of eupric sulfate andferrous sulfate. which results in the precipitation of euprous thimgvanatc. This step may be omitted if desired.

The next step in the process is the treatment, of the liquor with animal charcoal.- This treatment is preferably carried out by filtering the liquid through the animal charcoal. The animal charcoal removes substantially all of the remaining obnoxious substances which give the liquoriits 'harm- Qfif'ul qualities, disagreeable smell,-'taste and dark color. The liquor after passing through the animal charcoal is'substantiallyis 3 The treatment or the liquor with animal charcoal by filtering the liquor through a filter bed of animal charcoal permits'rapid treatment the liquor and'l have found,

sufficiently removes the obnoxious substances.

The liquor after the treatment with the animal charcoal m'ay, if desired, be run through an earth filter bed before being dis charged into the stream, in order to efl'ect 2o.ev en a more complete removal of the impurities .from the water.

The animal charcoal after it is fouled by the absorption of the obnoxious substances from the liquor, is recharred in order to revivity it for further use. The recliarring is carried out by heating the animal charcoal to about 650 degrees centigrade in a nonoxidizing atmosphere such; for example, as

heating it in a retort. The revivified ani "3e, inal charcoal may be re-used in this liquor purifying process, the charcoal going through a cyclical treatment of alternate use and revivification.

Certain industrial waste liquors which contain a minimum of solid impurities, sulfur and cyanogen compounds, for example the effluents from certain ammonia stills, may be treated directly with the animal charcoal without any preliminary treatment so of the liquor. In general however, the preliminary treatment is preferable as it decreases the amount of the animal charcoal necessary.

While the preferred embodiment of the t5. invention has been specifically described, it is to be understood that the invention is not limited to such embodiment and that some of the steps may be omitted and other varia; tions may be made within the scdpe of the ac following, claims. I -1 I claim: 4 1. The herein' described process of puritying liquprs containing phenoloid bodies, comprising, filtering the liquor through a filter bed of animal charcoal whereby the phenoloid bodiesare absorbed by the-'anianal charcoal, recharring the animal charcoal, and reusing the recharred animal charcoal for the treatment of more liquor; so substantially as described.

2. The herein described processof purify ing liquo'rs containing phenoloid' bodies, comprising, filteringv the liquor through a filter bed of animal charcoal in which the phenoloid bodies are absorbed by the anitially as described.

. le s s coal by heating it in a non-oxidizing atr'nosphere, and ice-using the recharred animal charcoal for filtering more liquor; substan- 3. The herein described process of purity ing liquors containing phenoloid bodies,

, comprising, filtering the liquor through a;

filter bed of animal charcoall whereby the; phenoloid bodies are absorbed bul the ani- 75. mal charcoal, recharring tlieani al charcoal by heating it to a temperature in the neighborhood of 650 degrees oentigrade'in the absence of free air, and re-using the recharred animal charcoal for the treatment of morejllquor.

4, The hereindescribed process of purifying Waste ammonia-still liquor, comprising, filtering the liquor through an inorganic filtering material, then filtering the liquor through a filter bed of animal charcoa, recharring' the animal charcoal and re-using the recharred animal charcoal for the treatmerit of more liquor; substantially as described. 90.

5. The herein described process ofpurifying waste ammonia still l1quor, comprising, allowing the solid substances to settle therefrom, filtering the liquor through a filtering material which removes the remaining solid substances but which does not remove the phenoloid bodies therefrom, and thereafter filterihg the liquor through a filter bed of animal charcoal whereby the Tphenoloid bodies are absorbed by the animal charcoal, recharring the animal charcoal and re-using the recharred animal charcoal for the treatment of more liquor; substantially as described.

o. The herein described process of purifying Waste ammonia still liquor, comprising, aerating the liquor, separating the solids therefrom by settling, filtering the liquor' through an inorganic filtering material, and thereafter filtering the liquor through a filter bed of animal charcoal, recharring the ani-' mal charcoal and reusing the recharred animal charcoal for the treatment of more liquor; substantially as described.

7. The herein described process of purity ing Waste ammonia still liquor, comprising, preliminarily clarifying the liquor, and filtering the clarified liquor through afilter bed of animal charcoal, recharring the animal charcoal and re-using the recharred animal charcoal. for the treatment of more -liquor; substantially as described.

8. The herein described process of purifying Waste liquors containing phenoloid 'bodies, comprising filtering the liquor through a filtering material containing iron oxid,'then filtering. the liquor through a filter-b nd of animal charcoal, recharring' the animal charcoal afteixit becomes fouled, and

renting the recharred animal charcoal for 18s.

the filtrationhf more liquor, substantially mal charcoal, recharrin the animal charas described. t I 0021] after it becomes fou ed, and reusing the 9. The herein described process of purifyrecharred animal charcoal for the filtratipn 10 ing waste liquor containing phenoloid of more liquor, substantially as described. 5 bodies, colnprlsing filtering the liquor In testimony whereof, I have hereunto through spent blastfurnace slag, then 51- set my hand. tering the liquor through a filter-bed ofani- CLEBURNE A. BASORE. 

